Thallium-containing wastewater treatment device

Abstract

The utility model discloses a treatment device for thallium-containing wastewater, and belongs to the technical field of wastewater treatment. The thallium-containing wastewater treatment device comprises a water storage tank, a first reaction tank, a second reaction tank, a third reaction tank, a fourth reaction tank and a fifth reaction tank which are connected in sequence, the water storage tank is used for removing particle impurities in the wastewater; the first reaction tank is used for adding sodium carbonate and removing heavy metals; the first reaction tank is used for adding sodium sulfide, the second reaction tank is used for adding sodium sulfide, the third reaction tank is used for adding a trapping agent, the fourth reaction tank is used for adding lime, and the fifth reaction tank is used for adding PAM. According to the device, thallium in the wastewater is effectively removed.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, and in particular to a treatment device for thallium-containing wastewater. Background Technology

[0002] Thallium (Tl) is a highly toxic heavy metal, far exceeding the toxicity of common heavy metals such as arsenic (As) and cadmium (Cd). Even trace amounts of thallium can enter the human body through the food chain or skin contact, leading to neurological damage, organ failure, and even death. Thallium is commonly found in sulfide ores, and the strategic metal antimony is also frequently found in sulfide ores. Therefore, in the mining, beneficiation, and smelting processes of antimony minerals, in addition to generating large amounts of antimony- and arsenic-containing wastewater, large quantities of thallium-containing wastewater are also frequently produced. The proper treatment of thallium-containing wastewater is crucial for the sustainable and green development of the antimony industry.

[0003] my country has extremely strict discharge standards for thallium-containing wastewater (≤5 μg / L), while some antimony smelting industries generate wastewater with high thallium concentrations, reaching 1-300 mg / L. Therefore, there is an urgent need for efficient high-concentration thallium-containing wastewater treatment technologies. Currently, there is limited research on the treatment of high-concentration thallium-containing wastewater both domestically and internationally. The main methods include direct precipitation, ion exchange, electrochemical deposition, coagulation, microbial methods, and adsorption. While each method has its own characteristics, they all have certain limitations. For example, direct precipitation, although simple and low-cost, consumes a large amount of reagents and is difficult to consistently achieve concentrations below 5 μg / L. Adsorption methods often use activated carbon and metal oxides (such as hydrated iron oxide) as adsorbents. Although they have high adsorption capacity, they suffer from problems such as material agglomeration and regeneration difficulties, limiting their practical application. Other treatment methods also suffer from problems such as excessively long treatment times, high costs, or secondary pollution. In particular, treatment methods for wastewater containing both antimony and arsenic are rare. Therefore, research on efficient treatment processes and methods for high-concentration thallium-containing wastewater is urgently needed. Developing an economical, simple, and efficient method for treating thallium-containing wastewater is particularly important to solve the industry-wide problem that currently hinders the sustainable development of the antimony smelting industry in the treatment of thallium-containing wastewater.

[0004] CN119551875A discloses a thallium-containing wastewater treatment device, including a sedimentation tank and a reaction tank located above and inside the sedimentation tank. The reaction tank includes an electrocatalytic tank, a pH adjustment tank, an electrocoagulation tank, a magnetic media inoculation tank, and a stabilization tank connected in sequence. A method for treating thallium-containing wastewater is also disclosed. Although this device has good thallium removal efficiency and stable effluent, the process flow is lengthy, the equipment is complex, and the operating cost is high.

[0005] How to efficiently remove thallium from wastewater is a technical problem that existing technologies need to solve. Utility Model Content

[0006] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a treatment device for thallium-containing wastewater, thereby solving the technical problem of how to efficiently remove thallium from wastewater in the prior art.

[0007] To achieve the above-mentioned technical objectives, the present invention provides a treatment device for thallium-containing wastewater, comprising a water storage tank, a first reaction tank, a second reaction tank, a third reaction tank, a fourth reaction tank, and a fifth reaction tank connected in sequence; the water storage tank is used to remove particulate impurities from the wastewater; the first reaction tank is used to add soda ash to remove heavy metals; the second reaction tank is used to add sodium sulfide; the third reaction tank is used to add a trapping agent; the fourth reaction tank is used to add lime; and the fifth reaction tank is used to add PAM.

[0008] In any embodiment, it further includes a first siphon water absorber, the inlet end of the first siphon water absorber being connected to the liquid surface of the water storage tank, and the outlet end of the first siphon water absorber being connected to the first reaction tank.

[0009] In any embodiment, the water storage tank is located at a higher position than the first reaction tank.

[0010] In any embodiment, the inlet end of the first siphon water absorber is provided with a filter screen.

[0011] In any embodiment, a sludge tank is also included; the sludge tank is connected to the bottom of the water storage tank, the first reaction tank, the second reaction tank, the third reaction tank, the fourth reaction tank, the fifth reaction tank, and the sixth reaction tank, respectively, and the sludge tank is used to collect sludge from the reaction tank.

[0012] In any embodiment, a filter press and a sludge pump are also included, wherein the feed end of the sludge pump is connected to the sludge tank and the discharge end of the sludge pump is connected to the filter press; the sludge pump is used to transport the sludge in the sludge tank to the filter press, and the filter press is used to filter the sludge.

[0013] In any embodiment, a water filter tank is also included, which is connected to the filter press and is used to receive the filter water after the filter press has treated the sludge.

[0014] In any embodiment, the filter tank is connected to the first reaction tank and is used to transfer the filtered water into the first reaction tank for treatment.

[0015] In any embodiment, the bottom of the first reaction tank is connected to the bottom of the second reaction tank, the bottom of the second reaction tank is connected to the bottom of the third reaction tank, the bottom of the third reaction tank is connected to the bottom of the fourth reaction tank, and the bottom of the fourth reaction tank is connected to the bottom of the fifth reaction tank.

[0016] In any embodiment, the filter press is a plate and frame filter press.

[0017] Compared with the prior art, the beneficial effects of this utility model include: the thallium-containing wastewater treatment device proposed in this utility model includes a storage tank, a first reaction tank, a second reaction tank, a third reaction tank, a fourth reaction tank, and a fifth reaction tank connected in sequence; the storage tank is used to remove particulate impurities from the wastewater; the first reaction tank is used to add soda ash to remove heavy metals; the second reaction tank is used to add sodium sulfide; the third reaction tank is used to add a trapping agent; the fourth reaction tank is used to add lime; and the fifth reaction tank is used to add PAM. The wastewater treated by these reaction tanks meets the national treatment standards, namely, the effluent contains TL≤5ug / l, Pb≤0.5mg / l, Sb≤0.3mg / l, As≤0.1mg / l, and the pH is between 6 and 9, thus effectively removing thallium from the wastewater. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the thallium-containing wastewater treatment device in Embodiment 1 of this utility model.

[0019] Figure 2 This is a schematic diagram of the water storage tank and the first reaction tank of the thallium-containing wastewater treatment device in Embodiment 1 of this utility model.

[0020] 1. Water storage tank; 2. First reaction tank; 3. Second reaction tank; 4. Third reaction tank; 5. Fourth reaction tank; 6. Fifth reaction tank; 7. Sludge tank; 8. Sludge pump; 9. Filter press; 10. Filter tank; 11. First siphon; 12. Second siphon. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model. Example 1

[0022] This embodiment provides a treatment device for thallium-containing wastewater, including a water storage tank 1, a first reaction tank 2, a second reaction tank 3, a third reaction tank 4, a fourth reaction tank 5, and a fifth reaction tank 6 connected in sequence; the water storage tank 1 is used to remove particulate impurities from the wastewater; the first reaction tank 2 is used to add soda ash to remove heavy metals; the second reaction tank 3 is used to add sodium sulfide; the third reaction tank 4 is used to add a trapping agent; the fourth reaction tank 5 is used to add lime; and the fifth reaction tank 6 is used to add PAM.

[0023] Wastewater entering storage tank 1 allows particulate impurities to settle. The wastewater then flows from the bottom of storage tank 1 through a pipe to the first reaction tank 2. Soda ash is added to the first reaction tank 2 to adjust the pH to 7-7.5. Adding soda ash to control the pH reacts with lead salts to form lead oxides, which are then precipitated and separated. The wastewater then flows from the bottom of the first reaction tank 2 to the second reaction tank 3. Sodium sulfide is added to the second reaction tank 3, maintaining the pH at 8-8.5. Sodium sulfide reacts with monovalent thallium in the water to form Tl₂S, which is sparingly soluble in water and precipitates out. Simultaneously, fine heavy metals are further removed by sulfidation. The water then flows from the second reaction tank 3 to the third reaction tank. In reaction tank 4, a trapping agent is added to the third reaction tank 4 to further adsorb, bridge, and precipitate the fine particles that have not yet settled in the above process. Then, the water flows from the third reaction tank 4 to the fourth reaction tank 5, where lime is added to adjust the pH to 9.5-10.5 to trap pentavalent arsenic in the wastewater and precipitate it out. Then, the water flows to the fifth reaction tank 6, where PAM is added for treatment. Through organic macromolecular bridging and coagulation, suspended fine particles in the water are further trapped and rapidly precipitated, thereby achieving efficient removal of thallium from the wastewater. The thallium content in the treated wastewater is as low as below 5 ug / L.

[0024] Based on the above embodiments, this embodiment also includes a first siphon water absorber 11. The inlet end of the first siphon water absorber 11 is connected to the liquid surface of the water storage tank 1, and the outlet end of the first siphon water absorber 11 is connected to the first reaction tank 2. The water storage tank 1 is located higher than the location of the first reaction tank 2. Under the action of gravity, water flows from the water storage tank 1 to the first reaction tank 2.

[0025] Furthermore, to prevent solid impurities from entering the first reaction tank 2 through the first siphon 11, a filter screen is provided at the inlet end of the first siphon 11.

[0026] Based on the above embodiments, this embodiment also includes a sludge tank 7; the sludge tank 7 is connected to the bottom of the water storage tank 1, the first reaction tank 2, the second reaction tank 3, the third reaction tank 4, the fourth reaction tank 5, the fifth reaction tank 6 and the sixth reaction tank 7 respectively, the sludge tank 7 is used to collect sludge in the reaction tank, and the outlet is connected to the feed end of the mud pump through a pipeline.

[0027] Based on the above embodiments, this embodiment also includes a filter press 9 and a sludge pump 8. The feed end of the sludge pump 8 is connected to the sludge tank 7, and the discharge end of the sludge pump 8 is connected to the filter press 9. The sludge pump 8 is used to transport the sludge in the sludge tank 7 to the filter press 9, and the filter press 9 is used to filter the sludge.

[0028] Based on the above embodiments, this embodiment also includes a water filter tank 10, which is connected to the filter press 9 and is used to receive the filter water after the filter press 9 has treated the sludge.

[0029] Filtered water is usually substandard and needs to be returned to the reaction tank for secondary treatment. In order to remove metal ions more thoroughly, in this embodiment, the filter tank 10 is connected to the first reaction tank 2 to transfer the filtered water to the first reaction tank 2 for treatment.

[0030] Based on the above embodiments, in this embodiment, the bottom of the first reaction tank 2 is connected to the bottom of the second reaction tank 3, the bottom of the second reaction tank 3 is connected to the bottom of the third reaction tank 4, the bottom of the third reaction tank 4 is connected to the bottom of the fourth reaction tank 5, and the bottom of the fourth reaction tank 5 is connected to the bottom of the fifth reaction tank 6. Water enters from the bottom of the reaction tank to facilitate the full reaction between the water to be treated and the added materials. In order to prevent impurities from entering the connected pipes, a filter screen is provided at the water inlet end of the pipes.

[0031] Based on the above embodiments, the filter press 9 in this embodiment is a plate and frame filter press, specifically a membrane filter press; the water storage tank 1 is a concrete water tank with a bottom and sides treated with resin for leak prevention; the sludge pump 8 is a corrosion-resistant sludge pump; the sludge tank 7 or the filter tank 10 is a steel shell lined with corrosion-resistant material, which can be a cylinder or a cube.

[0032] Based on the above embodiments, the first reaction tank 2 in this embodiment is equipped with a second siphon water extractor 12. If the treated water in the second reaction tank 3 meets the standards, the treated supernatant is taken out using the second siphon water extractor 12.

[0033] The following are examples of wastewater treatment devices used to treat wastewater:

[0034] Wastewater collected during an indium extraction process in a tin mine area was used. The wastewater contained thallium, as well as heavy metals such as antimony, arsenic, and lead. Its composition was: Thallium 3.24 mg / L, Sb 77.44 mg / L, Pb 85.34 mg / L, As 31.57 mg / L, and the pH value was 6. The treatment steps are as follows:

[0035] Wastewater enters a storage tank, where mechanical and large particulate impurities are first removed through pretreatment. It then enters the first reaction tank, where soda ash is added, stirred, and the pH is adjusted to 7. The reaction is carried out for approximately 60 minutes. The treated wastewater then flows from the bottom of the first tank into the second reaction tank, where sodium sulfide is added and the reaction is continued for 60 minutes to maintain a pH of 8. The treated wastewater then flows from the bottom into the third reaction tank, where PFS (polysulfone) is added to capture antimony and arsenic. The treated water then flows from the bottom into the fourth reaction tank, where lime is added to adjust the pH to 9.5 to further remove pentavalent arsenic. The treated wastewater then flows from the bottom into the fifth reaction tank, where PAM is added to the coagulation and clarification tank. The reaction is carried out for approximately 30 minutes, followed by settling for approximately 2 hours. Water samples are then sent for testing. Atomic fluorescence spectrometry analysis revealed that the TL (toluene-to-alcohol content) in the water was 0.11 ug / L, Sb was 0.11 mg / L, Pb was 0.23 mg / L, As was 0.05 mg / L, and the pH was 9.5. The settled sludge automatically flows into the sludge tank, and then is pumped into the membrane plate and frame filter press by the sludge pump. The filter water is returned to the first reaction tank, and the filter residue is sent to the slag yard for storage and then sent to a specialized disposal unit.

[0036] The specific embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model. Any other corresponding changes and modifications made based on the technical concept of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A treatment device for thallium-containing wastewater, characterized in that, The system includes a water storage tank, a first reaction tank, a second reaction tank, a third reaction tank, a fourth reaction tank, and a fifth reaction tank connected in sequence. The water storage tank is used to remove particulate impurities from the wastewater. The first reaction tank is used to add soda ash to remove heavy metals. The second reaction tank is used to add sodium sulfide. The third reaction tank is used to add a trapping agent. The fourth reaction tank is used to add lime. The fifth reaction tank is used to add PAM.

2. The thallium-containing wastewater treatment apparatus according to claim 1, characterized in that, It also includes a first siphon water absorber, the inlet of which is connected to the liquid surface of the water storage tank, and the outlet of which is connected to the first reaction tank.

3. The thallium-containing wastewater treatment apparatus according to claim 2, characterized in that, The water storage tank is located at a higher position than the first reaction tank.

4. The thallium-containing wastewater treatment apparatus according to claim 2, characterized in that, The first siphon water inlet is equipped with a filter screen.

5. The thallium-containing wastewater treatment apparatus according to claim 1, characterized in that, It also includes a sludge tank; the sludge tank is connected to the bottom of the water storage tank, the first reaction tank, the second reaction tank, the third reaction tank, the fourth reaction tank, the fifth reaction tank and the sixth reaction tank respectively, and the sludge tank is used to collect sludge from the reaction tank.

6. The thallium-containing wastewater treatment apparatus according to claim 5, characterized in that, It also includes a filter press and a sludge pump. The feed end of the sludge pump is connected to the sludge tank, and the discharge end of the sludge pump is connected to the filter press. The sludge pump is used to transport the sludge in the sludge tank to the filter press, and the filter press is used to filter the sludge.

7. The thallium-containing wastewater treatment apparatus according to claim 6, characterized in that, It also includes a water filter tank, which is connected to the filter press and is used to receive the filter water after the filter press has treated the sludge.

8. The thallium-containing wastewater treatment apparatus according to claim 7, characterized in that, The filter tank is connected to the first reaction tank and is used to transfer the filtered water into the first reaction tank for treatment.

9. The thallium-containing wastewater treatment apparatus according to claim 1, characterized in that, The bottom of the first reaction tank is connected to the bottom of the second reaction tank, the bottom of the second reaction tank is connected to the bottom of the third reaction tank, the bottom of the third reaction tank is connected to the bottom of the fourth reaction tank, and the bottom of the fourth reaction tank is connected to the bottom of the fifth reaction tank.

10. The thallium-containing wastewater treatment apparatus according to claim 6, characterized in that, The filter press is a plate and frame filter press.

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